Below is how to turn off autoplay feature on youtube you can try.
Youtube has added an autoplay feature which automatically begins a new video after the current videos you are watching ends.
How to turn off autoplay feature on youtube easily
To turn off the autuplay feature, click the blue Autoplay slider switch at the top of the right-hand column of Up Next videos. When you turn it off, YouTube remembered that even after both restarts and system restarts.
Youtube’s autoplay feature loads the next video but gives you a few second before it starts to play, so during those few seconds, click cancel to stop the autoplay.
Youtube’s autoplay feature doesn’t appear to mobile phones.